1 /* Test for the brk syscall wrapper. */ 2 3 #include <assert.h> 4 #include <errno.h> 5 #include <stddef.h> 6 #include <sys/syscall.h> 7 8 /* Data segment end. */ 9 extern int _end; 10 static char *begin = (char *)&_end; 11 12 __attribute__((noinline)) 13 static int test_begin(void) 14 { 15 int res = 0; 16 int tmp; 17 18 /* Check that a value at the break is inaccessible. */ 19 if (*begin) 20 res++; 21 22 /* Allocate one byte and check that the last byte is accessible and 23 initialized. */ 24 tmp = syscall(SYS_brk, begin + 1); 25 assert(tmp != -1); 26 if (*begin) 27 res++; 28 29 /* Deallocate one byte and check that the last byte is now inaccessible. */ 30 tmp = syscall(SYS_brk, begin); 31 assert(tmp != -1); 32 if (*begin) 33 res++; 34 35 return res; 36 } 37 38 __attribute__((noinline)) 39 static void test_updown(void) 40 { 41 int tmp; 42 size_t i; 43 44 #define MAX_SIZE 8192 45 /* Run up phase. */ 46 for (i = 0; i < MAX_SIZE; i++) { 47 tmp = syscall(SYS_brk, begin + i); 48 assert(tmp != -1); 49 } 50 51 /* Run down phase. */ 52 for (i = 0; i < MAX_SIZE; i++) { 53 tmp = syscall(SYS_brk, begin + MAX_SIZE - 1 - i); 54 assert(tmp != -1); 55 } 56 #undef MAX_SIZE 57 } 58 59 __attribute__((noinline)) 60 static void test_range(void) 61 { 62 int tmp; 63 64 tmp = syscall(SYS_brk, begin - 1); 65 assert(tmp == -1); 66 assert(errno == ENOMEM); 67 68 /* Unified limit for 64-bit and 32-bit version. */ 69 unsigned long long impossible_limit = 0xffffff4fffffffULL; 70 tmp = syscall(SYS_brk, impossible_limit); 71 assert(tmp == -1); 72 assert(errno == ENOMEM); 73 } 74 75 int main(void) 76 { 77 int res; 78 res = test_begin(); 79 test_updown(); 80 test_range(); 81 return res; 82 } 83 84
